Mail carrying aeroplane



R. FISHER Filed Nov. l0. 1930 MAIL CARRYING AEROPLANE July 21, 1931.

AINVENTOR: Zay f S' ef',

ATTORNEY.

ZZ/ L Patented .my la1,l 1931 .PATENT OFFICE noY FISHER,` or LosANGELES, CALIFORNIA nur. emma AEROPLANE Application me; November1o19so.sena1 No: 494,485.

, The object of the present invention is to provide improvements in theconstruction of mail carrying aeroplanes. More specifically my object isthe provision of a substantially D fire-proof, light and strongcompartment 1n the fuselage of such aeroplane. A further object is theassembling of such compartment in such a manner as to materiallystrengthen the framework of the aeroplane. Another object is improvedmeans for lockingthe compartment of my invention in a fashion acceptableto both users and authorities granting permits for the use of suchstructures.

In the appended drawings, forming part of this specification, isillustrated a structure embodying the invention. The various views of.these drawings are as follows;

Fig. 1 is a fragmentary view showing, in perspective, the rear portionofan aeroplane fuselage, y

Fig. 2 is a side elevation illustrating the more important parts of Fig.1,

AFig. 3 illustrates, in perspective, certain interchangeable safetydeposit boxes of the' structure, And Figs. 4 and 5 show details ofconstruction, the importance of which will hereinafter appear.

The mail compartment of the aeroplane comprisesoutside plates 5, 6, 7,8, fastened to said corner beams by suitable means, such as rivetin or awelding process. The inner walls of t e compartment includeiplates 10,-

11, 12. Between the outer and inner walls are placed layers of heatresisting material, such as asbestos sheets 13, v,14, 15, 16, etc.

The outer and inner walls of the compartment are made with corrugations,and it is important to note that these corrugations are pla-ced inopposed directions. The corrugations 7 a, of the Wall 7, for example,are shown diagonally inclined towards the left, while 5 the corrugations11", of the adjacent 'plate` The fuselage of the aeroplane may be'of 11,are `shown diagonally directed ,towards` the right. In this manner avery light and strong structure is provided.V In the various views ofthe drawings no attention has been paid to the direction of corrugationsin correspnding plates, my aim being merely to emphasize opposeddirections.

In prder to simplify this description, all six sides of the compartmentare shown s uare and of the same size, but they may, o course, bemodified to'suit particular fuselage design.

The important point I wish to bring out is, that the edges of theasbestos sheets over-lap each other. It is noticed, for instance, thatthe upper edge of the sheet 13 abuts the inner surface of sheet 16;fandthat the left edge -of the sheet 17'abuts the inneredge of sheet 13;

that the upper edge of sheet 14 abuts the inner surface of sheet 17, andso forth. lBy interlocking the sheets in this manner avery strong Aandsubstantially fire-proof structure is provided.

The outerv walls and the inner walls may consist of separate plates, asaforesaid', or continuous strips of corrugated steel may be bent toprovide all' four sides of the compartment, if desired. It is importantto note that the corrugations do not extend entirely to the edge of theplates, leaving a narrow flat Inargin around the corrugations forconvenience in assembling and fasteningy to -the corner beams, and inorder to provide air tight joints. This construction is best illustratedin Fig. 5f

The mail compartment of the aeroplane must, of course, be provided witha door. This door may be placed either inside the. fuselage or outside,as illustrated inFigs. 1 and 2. The door should also be of double orlrngated steel plate construction, and it is 9 provided with a pair ofpivotally hun locking levers 20, 21 for kengagement with rackets 22, 23of the wall 5. The levers `are shown 'interconnected by means of a bar24, on which 26 of the door.

i VA padlock 26 of any approved make is shown engaging these staples forthe purpose of maintaining the door locked. The levers 20, 21 and thebrackets 22, 23 are shown with is fastened,- a staple 25, adjacent togastaple lllU linteriitting beveled surfaces for the purpose of drawingthedoor tightly shut.

As shown in Fig. 2, the compartment is divided into two chambers bymeans of a partition 27. The larger bottom chamber is of a siz'e toreceive mail bags or loose mail in large quantities; The upper chamberis shaped to receive a series of standard size safe deposit boxes 30,31, etc. For convenience in transferring such boxes from one aeroplaneto another, in transit, these boxes may conveniently be insertableWithin a casing 28 of a size to fit the upper chamber of thecompartment. The casing is shown made with a hinged lid 29, the outerend of which is perforated, as at 29a,

= for engagement with a staple 30 of the casing.

When the lid 29 is closed the staple projects through this perforationfar enough to receive the padlock. Or any other suitable device 20 maybe embodied for holding a plurality of standard safe deposit boxes.

From the foregoing description it should be clear to those versed in theart, that my object r is to provide a mail compartment in an aeroplanefor convenience in handling valuable mail and for transferring such mailfrom one aeroplane to the other. AThe key to the padlock should, ofcourse, be in the hands of a person authorized to carry such, and theobject of providing space for receiving standard size safe deposit boxesis to permit iinancial institutions, such as banks, to transmitvaluablesin their own lock boxes. The advantage of this system is readilyappreciated. The institutions to which the boxes are addressed, are in aposition to send their messengers directly to the landing iield .to pickup their boxes, thus saving the time ordinarily con-l sumed'in routingsuch mail through the various post oiiice stations.

-I claim:

1. In an aeroplane, a mail compartment comprising, outer walls fastenedto the corner beams of the plane fuselage, inner Walls o within saidouter walls, and layers of asbestos sheeting intermediate said walls,the adjoining outer and inner walls being provided with corrugationsdirected in different planes.

2. In an aeroplane, a mail compartment comprising, outer walls fastenedto the corner beams of the plane fuselage, inner Walls within said outerWalls, and layers of asbestos sheeting intermediate said walls, theadjoining outer and inner walls being provided with corrugationsdirected in different planes, the said corrugations being somewhat,shorter than the walls, thereby leaving a flat margin around all foursides of the Walls for convenience in assembling and in order to obtainan air-tight joint.

3. In an aeroplane, a mail compartment comprising, outer walls fastenedto the corner beams of the plane fuselage, inner walls within said outerwalls, and layers of asbestos sheeting intermediate said walls, theadjoining outer and inner walls being provided with corrugationsdirected in different planes, and a hinged door in the side of saidcompart ment, said door comprising similarly corrugated outer and innerwalls and intermediate asbestos sheets, lock levers on said door forengagement with brackets of said compartment, and means on said leversand the said door for receiving a padlock.

4. In an aeroplane, a mail compartment comprising, outer walls fastenedto the corner beams of the plane fuselage, inner walls within said outerwalls, and layers of asbestos sheeting intermediate said walls, theadjoining outer and inner walls being provided with corrugationsdirected in different planes, said asbestos sheets being assembled withoverlapping edges, so that the edge of one sheet abuts the inner surfaceof the adjoining sheet vset at right angles thereto.

5. In an aeroplane, a mail compartment comprising, outer walls Jfastenedto the corner beams of the plane fuselage, inner walls Within said outerwalls, and layers'of asbestos sheeting intermediate said Walls, the adjoining outer. and inner Walls being provided with corrugations directedyin different planes, there being within said compartment a partitiondividing the compartment into an upv per chamber and a lower chamber,acasing forinsertion within said upper chamber, saidf casing of a sizeto receive a plurality of standard size safe deposit boxes, and meansfor closing and locking said casing for convenience in transferring the.casing from one plane to another.

6. An aeroplane fuselage comprising four corner beams extending fromfront to rear, plates securely fastened to said beams to form arectangularbox, a corresponding inner box, i and layers of fireresisting sheets occupyingA the space between the two boxes, there beingin the adjacentouter and inner walls of said boxes corrugationsextending in opposed directions, the corners and edges of said sheets l1 and inner walls, layers of sheets of re resisting material occupyingthe space between said outer and inner walls, said sheets being arranfedwith overlapping edges to form airtight ]oints,all of said compartmentWalls being made with corrugations leaving flat mar` vgins along alledges in order to provide airproof joints between Walls and theintermediate insulating sheets.

In testimony whereof I have hereunto affixed my signature.

ROY FISHER.

I iso

